Seeing a lot of warnings in projects with up-to-date eslint dependencies because of this.

Otherwise everyone who uses this config must add it to their own config.

airbnb's config allows dev dependencies in Gruntfile but that doesn't match Gruntfile.js: https://github.com/airbnb/javascript/blob/master/packages/eslint-config-airbnb-base/rules/imports.js#L85

Since we normally use the .js form, we should explicitly allow this in our config. Alternatively we could submit a PR to airbnb.

There should be a rule in eslint-config, that ensures that every file ends with a new line.

see: https://eslint.org/docs/rules/eol-last

https://eslint.org/docs/rules/indent#switchcase

This is horrible:

switch (someVar) {
case 'foo':
    return 'bar';
}

Much nicer:

switch (someVar) {
    case 'foo':
        return 'bar';
}

Currently npm gives a warning about a missing repository field. We should include:

• repository
• homepage
• bugs
• keywords
• engines

Airbnb allows parentheses around a single argument in an arrow function to be dropped unless there's a block body. This seems inconsistent to me - I'd prefer being able to drop them in both cases. It would also mean less fiddling about with parentheses: I find myself switching between block/non-block body much more frequently than changing the number of arguments in a function.

http://eslint.org/docs/rules/arrow-parens
https://github.com/airbnb/javascript/blob/master/packages/eslint-config-airbnb-base/rules/es6.js#L24-L26

In other words:

// good
const fn = foo => 'bar'; // as in airbnb
const fn = foo => {      // proposed change
  const bar = 'bar';
  return bar;
};

// bad
const fn = (foo) => 'bar'; // as in airbnb
const fn = (foo) => {      // proposed change
  const bar = 'bar';
  return bar;
};

Description

We currently actively support node version above 12.13.
In order to support M1 Mac series, we need to bump the version to node 16.

However, with the node 12 restriction in the package.json, it is not working.

To avoid this:

npm WARN [email protected] requires a peer of eslint@^3.19.0 but none was installed.

To avoid this:

npm ERR! peer dep missing: eslint@^4.9.0, required by [email protected]

In advance of 0.2.0 release.

Obviously nicer, and we're already using it here: https://github.com/LiskHQ/lisk/blob/1.0.0/.eslintrc.json#L9

Airbnb also seems to prefer it but hasn't included it yet: airbnb/javascript#296

Description

In order to allow new coding guide, we need to update the coding standards.

• Allow for of

'no-restricted-syntax': [
      'error',
      {
        selector: 'ForInStatement',
        message: 'for..in loops iterate over the entire prototype chain, which is virtually never what you want. Use Object.{keys,values,entries}, and iterate over the resulting array.',
      },
      {
        selector: 'LabeledStatement',
        message: 'Labels are a form of GOTO; using them makes code confusing and hard to maintain and understand.',
      },
      {
        selector: 'WithStatement',
        message: '`with` is disallowed in strict mode because it makes code impossible to predict and optimize.',
      },
    ],

• Allow await in for of loop

no-await-in-loop: "off"

Although we prefer to use Promise.all, but by nature we need loop await in some cases/

Additional Information

E.g. for validating test descriptions to avoid accidentally leaving in @now tags.

https://github.com/benmosher/eslint-plugin-import/blob/master/docs/rules/no-extraneous-dependencies.md

See LiskArchive/lisk-commander#369 for some

https://github.com/benmosher/eslint-plugin-import/blob/master/docs/rules/order.md

We need to have separate config files since we have different test runners at lisk-core repository at the moment.

Acceptance Criteria

• Have a base.js file for recommended config
• Have a jest.js file for jest config
• Have a mocha.js file for mocha config
• index.js file will remain the same to prevent a breaking change